GLENDALE HEIGHTS — Glendale Heights police and Bloomingdale firefighters are investigating the cause of an explosion and fire at Northstar Metal Products late Monday morning.

About 11:56 a.m., officials responded to a call and initiated mutual aid at the industrial building, 591 Mitchell Drive, Glendale Heights. Upon arrival, police and firefighters saw smoke coming from the building.

Two Northstar employees were injured; one was treated at the scene and released and the other was taken to GlenOaks Hospital to be treated for injuries that were not life threatening.

Police believe a piece of machinery inside the building exploded and caught fire. The cause is yet to be determined but appears to be mechanical in nature. Officials at the scene said there were no chemicals involved, and the public is not in any danger.

There are no signs of foul play, police said.

Estimated damage costs are unknown.

Railroad trains on the adjacent Canadian National track were halted through early Monday afternoon, along with vehicle traffic on Glen Ellyn Road between Gregory Avenue and Windy Point Drive. Both have been reopened.

Anyone with information on this incident should call the Glendale Heights Police Department at 630-260-6070.